Crank mechanism for cutting machines



Jun 30, 1925.

H. P. KELLY CRANK MECHANISM FOR CUTTING MACHINES 2 Sheets-Shoot l INVENTOR.

Filed March 31, 1924 Patented June 32, 1325.

an 7 and tease HERBERT P. KELLY, F SPRINGFIELD, MASSACHUSETTS, ASSIGNOR TO THE FISE B'UB- 7 BER COMPANY, OF GHICOPEE FALLS, TEASSACHUSETI'S, A CQRPQBATION OF PLASSAGHUSETTS.

CRANK. mnonamsia roe onrrme macnrm.

. Application filed. March 31, 1924. Serial No.- 703,0%.

To all it may'oo'noem: 1

Be it known that I, HERBERT P. KELLY, a citizen of the United States of America,

-residing at Springfield, in the county of Tflampden and State of Massachusetts, have invented certain new and useful Improvements in Crank Mechanism for Cutting Mamachines, 'by means of which strips of fabric of two different widths will be cut alternately. One object-of the invention is to provide a mechanism of this character in which the widths of both cuts may be adjusted independently, so that different combinations of fabric widths may be had. Further objects ofv the-invention reside in its reliability of operation, in its applicability to existing machines, and in its simplicitv 'of construction. Referring now to the drawings, Fig. 1 is a face view of that portion of the driving mechanism embodying my invention;

median section; V Fig. 3 is a partial view similar to-Fig. 1, but with the parts in a difierent operative position;

Fig. 4: is a s1de elevation of a bias cutting .machine to which my invention has been applied;

Fig. 5 is a detail side view of Fig. 1 showing the adjusting scales; I Fig. 6 is a sectionon line 6-6 of Fig. 2; and

Fig. 7 is a section on line 7-7 of Fig.2. Figs. 8 to 11 inclusive are diagrammatica views illustrating the operation of the device.

The bias cutting machine to which the invention is applied may be of any desired type, that shown in Fig. 4 being ofthe type shown in ,the patents to Bolton 942,164, and

Wegner 1,384,984, to which reference may be made for a more extended description. The feed'of fabric to the cutting mechanism is controlled by the"oscillation of a gear.

which, by'means of a suitable segment 10 ratchet mechanism, causes interpinion and Fig. 2 1s a side view thereof, partlyin mittent rotative movement of the fabric feed roll 11. Power for causing these oscillations is transmitted to the gear segment by a link 12 having its lower end pivoted to a block 13 sliding in vertical ways in the'machine frame. a link 14C with the crank mechanism forming the present invention.

On ashaft 15 (Figs. 1, 2, and 4:) rotated The-block in turn is connected by continuously during the operation of the machine, is fixed a crank block 16 (Fig.2) provided with radial ways 17." A rectangular block 18 is fitted to slide in these ways,"

and through the block is screwed a stud'19 (Fig. 6). Through both the blockand the baseof the stud is threaded an adjusting screw 20 extending the length of the crank and having a handle 21. -An enlargement 22 on the screw bears against one side of aplate '2 3'fixed to the end of the crank (Figs. 1

and 2), and a collar 24 pinned to the screw at 25 bears on the other side of theplate. The screw is thus free to turn in the plate but cannot move endwise, any turning causing a radial adjustment in the ways of the block and stud.

011 the stud 19 are mounted, in longitudinal succession, a sleeve 26 and a gear 27, the latter being keyed to the stud and therefore having no rot-ative-movement with respect to crank 16. Sleeve 26 passes loosely through a hole me long block 28 running on bearing surfaces 29 on a forked guide 30 terminating in an ofiset hub 31. The link 14 previously referred to is secured to this hub as by a thread and lock nut connection 32. The sleeve 26 preferably has a rectangular extension 33 fitting into the slot between the guides 17, as shown in Fig. 6, to hold the crank 16 and block 28' servingas separators and also for the" attachment of an index :plate as will be later described.

Besides carrying the stud 19 on which is .mounted the gear 27, the long block 28 also carries a stud 35 pinned thereto at 36. Freely rotatable on this stud, which is formed with a retaining head 37 is a second. gear 38 twice the size of the first gear 27. The pivots of the two gears are by this means mounted in block 28 at a fixed distance apart so that the gears will at all times be-in proper mesh. Fixed to the face of this second gear as by screws 39 are gibs 40, forming between them a slideway to receive ablock 41. .Screwed'into' this block is a stud 42 having a flange 43 at its lower end. Through this block and stud passes a threaded adjusting screw 44, secured by a flange 45 and a collar 46 to a plate '47 fas tened tothe ends of the gibs as was the case with screw 20. By rotating this screw the length of the crank arm formed by the span between the center of studs 35 and 42 may be varied. I A sleeve 48 surrounds stud 42 having'a'. rectangular extension 49 fitting .into the gap between the gibs to-prevent rotation, and side extensions 50serving as spacers and also for the attachment of an index plate as will be described. The sleeve forms a bearing upon which a link 51 pivots into tight wedging action with the gibs. In

order to 'indicatethe positions of adjustment of the two slides the extensions 34 and respectively of the two sleeves 26 and 48 are provided with index plates55 and 56, best shown in Fig. 5. These plates co-operate with graduations 57 and 58 respectively, secured to'the' side of the crankblock and .to

the gibs 40.

' yet alwayson one side of its center (consid- The various elements going to make up the device having been thus described, it remains" to consider their operation as a unitary combination. As. the crank 16 rotates the small gear 27 .will be carried with. it. It will be followed in thistravel by gear 38, which by the connecting block 28 running in the forked guide 30 is always kept at thev proper meshing distance from gear 27 and ering the matter as referredto a fixed part of the machine). As gear 38 is free to rotate while gear 27 is not, and as the large gear is always on one side of the smaller during the latters circular sweep at the end of the crank arm,the large gear will be rotated during each revolution of the crank a circumference on its pitch line equal to the pitch circumference of the small gear. The size of the large gear being twice the smaller, it follows that during each revolution of the crank 16 the-large gear 38 will have imparted to it a half revolution. The operation is shown diagrammatically formed between shaft 15. and'stud 19, form-' ing what may be termed the main crank, is indicated by 60, and the crank formed betweenstuds 35 and 42 isindicated by 61. It is,,of course, the distance between the shaft 15 and the pivot 65 in the different positions that determines the throw of the crank. Figs. 9 and ll'represent the conditions of the parts at oneend of'the throw on successive revolutions of the main crank. It

of this is to cause the throw ofthe entirecrank mechanism in the position of Fig. 8 to be greater than in Fig. 10 by an amount equal to twice the .radius of the small crank.

Following the mechanism through a complete cycle, the following sequence of operations occurs. Starting with the position of Fig. 9, which may be considered as the position in which segment 10 (Fig. 4) is lowered, the first half revolution -of the main crank causes the stud 42 to be raised to the position of Fig. 10. This gives a throw to the link pivot 65 equal to the difference between distance I) (Fig. 10) and distance a (Fig. 9). A succeeding half revolution of the main crank will retract the link pivot to position of Fig. 11, in which its distance a from the main shaft is the same as in Fig. 9. One more half revolution brings the link pivot to a point spaced a distance 0 from the main shaft, consequently giving to the link and to the segment 10 a throw greater than on the preceding upward movement by an amount which, as stated before, is twice the radius towhich the small crank is set. The final half revolution, which completes the cycle of two revolutions of the main shaft, brings the parts: again to the position of Fig. 9.

Having thus described my invention, I claim:

1. A variable throw crank mechanism comprising a crank having a radial guideway, a block adjustably mounted in the guideway, a gear secured to the block against rotation, a second gear twice as large as and meshing with the first, a second block joining thepivots of both gears, a guideway secured to the second gear, a pivot adjustably secured in the second guideway, a link having one end guided for substantially rectilinear movement and the other will be observed that although stud 42 is 3 end having sliding connection with the secgear fixed on the crank pin, a second ear ond blook, and a second link connecting the twice the size of the first and mounte so first link with the adjustably mounted that its pivot Will always remain a constant to pivot. distance from the pivot of the first gear but '5 2. A variable crank mechanism adapted on one side thereof, and a crank pm fixed to produce alternately different throws, comto the second gear. prising a crank, a crank pin fixed thereon, a HERBERT P. 

